Actually Accurate

untrusted instrument in the aircraft all of a sudden is now the most reliable instrument in the aircraft. It’s a total phase change.” — Scott Philiben www.eaa.org 83 “You would suspect that new fuel sender technology should look robotic or something. To make it look like the legacy float sender without any of the legacy issues is a little deceptive in some ways, but it’s worked fantastically.” — Scott Philiben CiES stocks arms in half-inch increments and can quickly pro- duce other working variations. A CNC rod bender in the shop whips out new arms in seconds. Senders are built from standard parts. The unit is attached with a basic bolt pattern housing orientation of 12, 3, 6, and 9 o’clock used almost universally in aircraft. When an order comes in for a configuration previously produced, it is built to order from parts in stock. For new orders, customers send their current sender and an illustrated parts catalog image or photo. CiES documents the new configuration and submits it to the FAA for the next STC update. “It’s straightforward for us to handle experimental aircraft requests since they typically were designed to use a resistive sender,” Scott said. “Simply making one of the stock configurations is rela- tively straightforward.” CiES is currently supporting Cessna twin-engine aircraft that use the penny cap capacitive system and replacing them with CiES sen- sors that are more straightforward, reliable, and accurate. LOCATION AND INSTALLATION “TELL ME WHERE it needs to go, and we can typically accommodate that,” Scott said. The CiES unit will fit into any aircraft and can be mounted on the top, side, bottom, or interior of a fuel tank. For example, units for Beechcraft Bonanzas and Barons are installed on top while units for Wacos bolt to the bot- tom. Piper Malibu and Cessna TTx aircraft have them mounted on the inside of the tank. A rib side mounting is suggested for new experimental aircraft since it centers the unit on the tank and makes it less pitch sensitive. The number of senders in any given tank depends upon its size and shape. A Baron with its long tanks has three senders. High-wing aircraft with straight wings, such as a Cessna 210, have only one sender per tank whereas a low-wing Bonanza with its higher dihedral for stability has two senders. Cirrus SF50 jet air- craft have three per tank, and other aircraft with even larger tanks have four. Installation takes four hours per sen- sor on average. Three wires for power, ground, and signal are required since the active sensor requires electricity to oper- ate the microprocessor. Actually Accurate Fuel Transducter views 84 October 2019 LEGACY LOOK “YOU WOULD SUSPECT that new fuel sender technology should look robotic or some- thing,” Scott said. “To make it look like the legacy float sender without any of the legacy issues is a little deceptive in some ways, but it’s worked fantastically.” The mean time to failure of a CiES unit is more than 90,000 hours. CiES initially suspected that promoting the benefits of its new system would be a hard sell since it looked very much like the old senders. In the beginning, this proved to be true. “Now that we have been out there and people have been talking about us, it’s almost a religious experience for them having accu- rate fuel level in a GA aircraft, and they spread the word,” Scott said. “It doesn’t mat- ter to anybody what the technology looks like inside doing those things. All that mat- ters is that you get good information in the cockpit.” FIRST RV-10 INSTALLATION WHEN LAYNE BOGULAS, EAA 868068, fin- ished building his RV-10 in 2016, it had a conventional fuel sending unit. When he decided to install the CiES system, in addi- tion to removing the wing tanks and installing the senders, the unit needed to be calibrated and mapped since his was the first RV-10 installation. Due to the dihedral of the RV-10 wing, one fuel sender is on the bottom of the tank and one at the top. Since the top float can only go so high, the sender starts measuring after 7 gallons of fuel has been used and measures from 30 gallons down to zero. The system integrates with his Garmin G3 avion- ics, and he has flown a couple of hundred hours with it. “When you don’t have to second-guess things, it makes it easy not to worry about it,” Layne said. “If it says you’re 10 gallons down, you’re 10 gallons down. If it says 9.8, it’s 9.8. You don’t get erratic fuel sensing when the plane jostles around in rough weather. It’s spot on all the time.” OTHER COMPONENTS IN ADDITION TO accurate fuel level technology, CiES is working on other fuel system components. It has been working with RDD Enterprises in Redmond, Oregon, for automated tank switching for its LX7, which is a modification of the Lancair IV-P with similar speed capacities but more docile handling characteristics and an airframe parachute. Accurate fuel quantity technology makes intelligently automated tank switching feasible. “Now that you have a fuel level system that’s reliable, you can start automating processes that used to rely on the pilot,” Scott said. This system can assist the pilot in automating the selection of a fuel tank, keeping, for example, two LX7 90-gallon wing tanks within 1 gallon of each other throughout a flight. CiES is also working on a prototype app that reports a digital fuel readout to your cellphone. “You can sit in the FBO and watch your airplane be fueled to the level that you specified and see it visually happening in front of you,” Scott said. It’s been more than half a dozen years since Scott started on a quest to solve this age-old aviation problem, and his persistence has finally paid off. “One of the things people warned us about when we started is that you’re going to get your pants sued off, as pilots will find a way to run out of gas,” he said. “Thankfully, with over 29,000 senders in the field right now, we haven’t had, to date, a single pilot starve an engine or run out of fuel with our system onboard.” Beth E. Stanton, EAA 1076326, is a recovering competition aerobatic pilot who is now working on ratings to become a CFI. She can be reached at bethestanton@gmail.com. RV Fuel Sender www.eaa.org 85